Question: "probe-rs info" command increases the LED blinking frequency??

[Dicklessgreat]

It is not a direct bug in this demo, but the behavior is a little concerning, so I thought I would report it.

Environment: Windows 10, WCH-LINK, CH32V203 evaluation board (I don't know the name. Please refer the attached picture )

What I did:

• Build this repo(and prepare flashing binary)
• flash binary via USB with wchisp(now the board started blinking "slower")
• disconnect USB
• connect WCH-LINK with the board and with host machine's USB port(now the board run the blinking program that has received from USB)
• on terminal, probe-rs info(which shows "Unknown Manufacturer Code"), then the board's LED blinking "faster"
• disconnect WCH-LINK from host machine USB port(then, board stop blinking)
• reconnect WCH-LINK, then, the board LED starts to blink "slower"
• you can reproduce "faster" blinking by probe-rs info

I builded and flashed the program of this repo over USB with wchisp. I actually thought the LEDs were blinking slowly at this point, but I didn't really care and decided to move on. Next, I connected WCH-LINK to try probe-rs to see if I could flash it (I did this without knowing that probe-rs did not yet support ch32v203) and ran the probe-rs info command to check if it recognized correctly, and then, the LED on the board suddenly blinked faster.

My guess is that the CPU clock was not set correctly at the time of rcc.apb2pcenr.modify(), and at some procedure during the execution of probe-rs info refreshed the CPU clock and it had run at 8MHz.

I would be happy to hear any insights you may have come up with from the above. Thanks.

[andelf]

Thanks for your report. That's interesting

• This repo is lagging behind current development on CH32V MCUs. I need to figure out a way to manage all hal crates of different MCU families(with both minor differences or different peripherals)
• The main.rs here doesn't initialize the RCC part. So this might be the problem. (more precisely, this should be related to some FLASH options)
• While developing ch58x-hal, I found that if some code is executed from SRAM instead of FLASH, it'll be about 4x times faster or so.
• Another hal impl is at https://github.com/ch32-rs/ch32v20x-hal

[Dicklessgreat]

Thanks, I'll go deeper later. I made a discussion at probe-rs project

[Dicklessgreat]

Sharing missing context: I forgot to write how frequent it blinks. It takes around 1 second per toggling state(lit to not lit, or not lit to lit) when it is "slow"(or, before probe-rs info) And it takes around 0.25 second per toggling state when it is "fast"(or, after probe-rs info)